A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

The Rideau Canal , also known as the Rideau Waterway, connects the city of Ottawa, Ontario, Canada on the Ottawa River to the city of Kingston, Ontario on Lake Ontario. The canal was opened in 1832 as a precaution in case of war with the United States and is still in use today, with most of its...

Rideau Lakes is a township located within Leeds and Grenville County in Eastern Ontario, Canada. The township was incorporated on 1 January 1998 by amalgamating the former townships of North Crosby, South Crosby, Bastard, South Burgess and South Elmsley with the village of Newboro.Rideau Lakes lies...

The United Counties of Leeds and Grenville are located Ontario, Canada. The population, as of the 2006 census, was 99,206. The United Counties have a land area of . Leeds and Grenville are located in the subregion of Southern Ontario named Eastern Ontario, and front on the St. Lawrence River and...

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, that was built in 1831 and completed in 1832 to tame the mile-long series of rapids and falls that runs through the Jones Falls.

History

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

Thomas McKay was a Canadian businessman who was one of the founders of the city of Ottawa, Ontario. He was born in Perth, Scotland and became a skilled stonemason...

. When completed in 1832, the Jones Falls dam was the largest dam in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, a big accomplishment in engineering. In order to keep the water in control during construction, two sluices, artificial channels for conducting water, were kept open in the dam. The first was near the base of the dam on its east side. A second sluice

Sluice

A sluice is a water channel that is controlled at its head by a gate . For example, a millrace is a sluice that channels water toward a water mill...

was put in on the west side of the dam, about 20 feet (6 metres) above the base. To make the switch from the lower to upper sluice

Sluice

A sluice is a water channel that is controlled at its head by a gate . For example, a millrace is a sluice that channels water toward a water mill...

, the outlet of Sand Lake was blocked off. It is called the ‘Whispering Dam’ because if a person stands at one edge of the dam, near the top, and another person stands at the other edge, the two can communicate quite well over a distance of almost 360 feet (110 m). This is because of the shape of the dam in an arch and the use of sandstone rather than mortar. This abnormal quality was not planned, just a delightful result of the design.

Statistics

At Jones Falls, boats rise and fall almost 60 feet via a set of four canal locks, and a dam, nicknamed the Whispering Dam, which holds back the 60 feet of water. The dam is approximately 360 feet long, 60 feet (18 m) high and 27 feet (8 m) thick at the base. It was built with large sandstone blocks that were hauled by horse-teams to and shaped on site. No mortar or cement was used in this dam. The blocks were set in a giant arch

Arch

An arch is a structure that spans a space and supports a load. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures.-Technical aspects:The...

, with the pressure of the water behind the dam pushing the perfectly-dressed blocks together, like an arch used in building structures.